Vehicles operating in an autonomous mode (e.g., driverless) can relieve occupants, especially the driver, from some driving-related responsibilities. When operating in an autonomous mode, the vehicle can navigate to various locations using onboard sensors, allowing the vehicle to travel with minimal human interaction or in some cases without any passengers.
For safety concerns, autonomous driving and driver assisted technologies require a safety monitoring system to alarm and/or alert a human driver to take over driving tasks for an ADV in potentially unsafe circumstances. An example of an unsafe circumstance arises when any critical subsystems of an autonomous driving system (ADS) of the ADV fail to generate a solution or an error in the ADS has occurred.